Hot Deformation Mechanisms in AZ31 Magnesium Alloy Extruded at Different Temperatures: Impact of Texture

Metals

Kamineni Pitcheswara Rao³  Yellapregada Venkata Rama Krishna Prasad¹  Joanna Dzwonczyk²  Norbert Hort⁴ 

[1] Processingmaps.com, No. 2/B, Hospital Extension, Vinayak Nagar, Bangalore 560075, India;Lightweight Metallic Materials, SKF Engineering & Research Centre, Utrecht Area, Netherlands;;Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR, ChinaMagnesium Innovation Centre, Helhmoltz Zentrum Geesthacht, Max-Planck-Straße 1, Geesthacht 21502, Germany;

关键词: AZ31 magnesium alloy;    extrusion temperature;    fiber texture;    processing maps;    kinetic analysis;   

DOI  :  10.3390/met2030292

来源: mdpi

【 摘 要 】

The hot deformation characteristics of AZ31 magnesium alloy rod extruded at temperatures of 300 °C, 350 °C and 450 °C have been studied in compression. The extruded material had a fiber texture with <100> parallel to the extrusion axis. When extruded at 450 °C, the texture was less intense and the <100> direction moved away from the extrusion axis. The processing maps for the material extruded at 300 °C and 350 °C are qualitatively similar to the material with near-random texture (cast-homogenized) and exhibited three dynamic recrystallization (DRX) domains. In domains #1 and #2, prismatic slip is the dominant process and DRX is controlled by lattice self-diffusion and grain boundary self-diffusion, respectively. In domain #3, pyramidal slip occurs extensively and DRX is controlled by cross-slip on pyramidal slip systems. The material extruded at 450 °C exhibited two domains similar to #1 and #2 above, which moved to higher temperatures, but domain #3 is absent. The results are interpreted in terms of the changes in <100> fiber texture with extrusion temperature. Highly intense <100> texture, as in the rod extruded at 350 °C, will enhance the occurrence of prismatic slip in domains #1 and #2 and promotes pyramidal slip at temperatures >450 °C (domain #3).

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.